Abstract 13670: Single versus Serial Measurements of Cardiac Troponin in the Evaluation of Emergency Department Patients With Suspected Acute Myocardial Infarction

Abstract

Introduction: Chest pain is among the most common reasons for emergency department (ED) presentations. However, most patients are low risk for acute coronary syndrome (ACS) with low cardiac adverse outcomes. Biomarker testing with troponins is the mainstay of initial assessment for ACS. Although serial troponin testing can improve diagnosis of ACS, in clinical practice, some patients deemed to be low risk are discharged after a single negative troponin measurement. Our study evaluated the safety of single-troponin rule-out strategy using a conventional troponin assay. Hypothesis: We assessed the hypothesis that there is no significant difference in the clinical outcomes of patients deemed low-risk and discharged after a single negative troponin compared to patients discharged after serial troponin measurements. Methods: This is a retrospective study of ED encounters from January 2015 to December 2017 across 13 community emergency departments within an integrated healthcare system in Southern California. The study cohort includes adult ED encounters evaluated for suspected ACS with a HEART score and an initial conventional troponin-I below the level of detection (<0.02). Multivariate logistic regression model was performed to evaluate the association between testing strategies and clinical outcomes. Results: Among 27,918 patients with an initial troponin measurement below the level of detection, 14,459 (51.8%) were discharged after a single measurement, and 13,459 patients (48.2%) had serial troponin orders. After adjusting for cardiac risk factors and comorbidities, there was no statistically significant difference in the primary outcome of AMI or cardiac mortality within 30 days between the two groups (single troponin 0.4% vs. serial troponin 0.4%, OR 1.41, 95% CI (0.96-2.07)). Single troponin was associated with a lower rate of CABG (OR 0.24, 95% CI: 0.11-0.48) and invasive coronary angiogram (OR 0.46, 95% CI: 0.38-0.56). Conclusions: When compared to serial troponin testing, discharge after a single negative troponin is routinely done among ED patients, and appears safe based on current physician decision making with no difference in rates of 30-day cardiac mortality and AMI.

Troponin Testing in the Emergency Department—When 2 Become 1

“…Unfortunately, specific data on the HEART score vs outcome per participant are not reported. However, in Table 2 of the study by Wassie et al, 5 the authors reveal that the patients who were discharged after a single blood test had a lower HEART Downloaded From: https://jamanetwork.com/ on 03/14/2021 score than those who underwent serial testing. Thus, the single troponin group had a lower risk of ACS or major adverse cardiac events (MACEs).…”

“…Wassie et al 5 address the single vs serial troponin question with a retrospective review of prospectively collected data from a respectable 27 918 patients, almost evenly split between those with a single troponin order (14 459 [51.8%]) and those with serial troponin orders (13 459 [48.2%]).…”

“…They identified 48.4% of patients as low risk for a MACE, with an NPV of 99.9%, concluding that a modified HEART score of 3 or less, with the use of a single hs-cTn T measurement (Elecsys [Roche]), appeared to be the optimum early discharge strategy for suspected ACS. 8 In the United States, where Wassie et al 5 performed their study, hs-cTn is not yet commonly used. Also, there is significant physician variability in practice and considerable concern regarding the legal implications of a failed diagnosis, with missed myocardial infarction remaining the top reason for medical malpractice actions.…”

“…However, hospitalization and additional cardiac testing also carry a risk. It is a surprising finding in the study by Wassie et al 5 that half of ED clinicians used a single troponin measurement before discharging patients with chest pain. This has not been previously described in a study of this size, in which 30-day outcome data were available.…”